#!/usr/bin/env node

const {Readable} = require('stream');
//const Read = require('stream').Readable;
const rs = new Readable();
let c = 'a'.charCodeAt(0);

rs._read = ()=>{
  rs.push(String.fromCharCode(c++));
  if (c==='z'.charCodeAt(0)+1) rs.push(null);
}

rs.pipe(process.stdout);

